In 802.1X, the heavy authentication work is done on which component?

• A. Authenticators
• B. Clients
• C. Both authenticators and clients
• D. Neither authenticators nor clients

Answer: (D)

In 802.1X, authentication is a three-party process: the supplicant (client), the authenticator (like a switch or wireless AP), and the authentication server (often a RADIUS server). The heavy lifting—verifying credentials, applying access policies, and deciding allow or deny—happens on the authentication server. The authenticator’s job is to forward EAP messages between the client and the server and to gate the port based on the server’s decision. The client initiates the process and participates in the EAP exchange, but it doesn’t perform the central verification or policy enforcement. Since the most substantial authentication work is done by the authentication server and that component isn’t listed, the correct choice is that neither the authenticator nor the client handles the heavy authentication work.